Plastic stock



Y PROCESS or snrAnA 'rrive THE-CONSTITUENT MATERIALS or 'nrnrto os THERMoQ" I I Iifo Drawing.

was Sept 29.1925.v

HENRY nsHomvEoK, or DORCHESTER, MASSACHUSETTS.

PLASTIC STOCK.

' TddZZ whom it"may concern:

' Be'it known that I,

HENRY P. Snowmen,

citizen of the United States, residing at fesses of Separatingthe Constituent Mate- -"rials of Fibrous Thermoplastic'Stock, of

,whichfthe following is a specification.

' In. my present invention I contemplate.

.fthe recovery of various constituents 0f glfibrous thermo-plastic materials and particularly from the scrap from such materials. In certain arts where blanks are'cut from sheet stock of this sort, there is a very large amount of scrap thatheretofore has been waste or hasbeen only imperfectly salvaged. The difiiculty seems to have re-' 1 sided in the inability to separate, without the fibrous body.

greatloss, the thermo-plastic binders from In discussing my invention, Ishall make 1 particular reference 'to' such a characteristic material utilizedfin the "manufacture. of.

shoes, as illustrative of the-practices of my invention and as indicating an art in which "there is practical demand for the improvementsinvolved.

Box toe stock comprises a in which isa binder such as rosin, bitumen Jor the like.

fibrous body By reason of; their use, the

bindersinfthe material are selected with reference to their insolubility in water. By

reason of certain physical characteristics 1 which seem to be common to these binders, they tend 'in' certain conditions to powder or to become very finely divided. The problem is to get the fibre free from the gums 1 r. and other binders and at the same time to save the binders.

In accordance with my invention I beat out mechanically the'material to be worked v on, such as the scraps of box toe felt. This preferablyefiect in the presence of water, reducing the mass to a wet pulp. This pulp I comprises the fibres in a free condition and the binder in afine stateof subdivision so] that it .is in suspension in the water or.

may be so suspendediftheQscrap is beaten .5 out dry. r F r I I next separate the" water" withthe-"sus-j bre, as by screening, centrifuging-, .press?,

'ing, etc.,'leaving the fibre free, afterwhich it may be washed or otherwise treated. 1

I now heat the water with its suspended thermo-plastic binder.

or other binder material. tion it may be readily filtered out. By "1 heating to a higher temperature, say about 140? F., the binder may be made to coagu-- late, forming larger particles whichfare If: 7 readily'separated from thefwater. At higher temperatures, say 160 F. the bind- "ers are more completelycoagulated and are easily removed. By effecting coagulation of the binder below thefboiling point'ojfthe Water, the recovered productconstitutes" I r f r a novel gumming substance of uniquecharr i acter; Thus the fibre and the binder are recoverable for the various commercialuses -to which they are adapted asffor-si'zesyforq paper. making, for the making of 't-hermoplastics or for'use'again in box toe stock. a

terials containing binders.

' What I therefore claim and desireftoj3 secure by Letters Patent is:

1. The method. of cut materials of fibrous thermo-plastic stock containing a friable thermo-plastic binder consisting in mechanically disintegrating the stockin the presence of water to reduce the binder so as to be suspendable in water, in

removing the binder in a state of suspension,

from the fibre, in thermally coagulating the jf' binder and in separating it from the water."-. 2. Thefmethod of recovering the con'stitu 1 -ent materials of fibrous thermo-plastic stock p containing 2. friable thermo-plastic" binder consisting in beating out the stock in water 7 g to form a pulp with the binder in suspen' m pended thermo-plastic binder from the 1 1 At, this stage the matter of temperature becomes important. 'To recover the binder in a finely divided V state it should be heated to about or well below the fusing, point of the gum v i In this condi-f recovering the constituf i the binder to a finely divided state free from the fibre in Washing the binder so divided 10 to separate it from the fibre mass, and in recovering the finely divided binder from the Water by filtering.

In testimony whereof I afiix my signature.

HENRY P. SHOPNECK 

